In semiconductor processing, physical vapor deposition (PVD) is a conventionally used process for deposition of materials atop a substrate. A conventional PVD process includes bombarding a target comprising a source material with ions from a plasma, causing the source material to be sputtered from the target. The ejected source material may be accelerated towards the substrate via a negative voltage or bias formed on the substrate, resulting in a deposition of the source material atop the substrate. In some processes, following the deposition of the source material, the deposited material may be resputtered by bombarding the substrate with ions from the plasma, thereby facilitating a redistribution of the material about the substrate. During the PVD process a magnetron may be rotated near a backside of the target to promote uniformity of the plasma.
Some conventional radio frequency (RF) PVD process chambers provide RF energy to a target via electrical feeds coupled to the target. The inventors have discovered that deposition processes in conventional PVD chambers having RF energy coupled to the target often yield non-uniform deposition profiles on substrates being processed.
Accordingly, the inventors have provided improved methods and apparatus for PVD processes that may provide more uniform deposition profiles on substrates being processed in a PVD process chamber.